Suppressor device for automatic on-off sprinkler head

ABSTRACT

A SUPPRESSOR DEVICE FOR A SPRINKLER HEAD HAVING A CONTROL CHAMBER AND A PRIMARY INTERCONNECTED BY A PASSAGE INCLUDING A UNIDIRECTIONAL VALVE MEMBER FOR PERMITTING FOW THROUGH THE PASSAGE FROM THE PRIMARY CHAMBER TO THE CONTROL CHAMBER WHEN THE PRESURE IN THE PRIMARY CHAMBER EXCEEDS THAT IN THE CONTROL CHAMBER AND PREVENTING FLOW IN THE OTHER DIRECTION THEROUGH THE PASSAGE FROM THE CONTRL CHAMBER TO THE PRIMARY CHAMBER WHEN THE PRESSURE IN THE CONTROL CHAMBER EXCEEDS THAT IN THE PRIMARY CHAMBER.

W. J. GRENIER Nov. 7, 1972 2 Sheets-Sheet 1 Filed May 28, 1971 I m F W/LFRED GRE/V/ER ATTOR/VEX Nov. 7, 1972 w. J. GRENIER 3,702,160

SUPPRESSOR DEVICE FOR AUTOMATIC ON-OFF SPRINKLER HEAD Filed May 28, 1971 2 Sheets-Sheet 2 HY ZZhemf/o 2 111 1.6027

United States Patent Office 3,702,160 Patented Nov. 7, 1972 ABSTRACT OF THE DISCLOSURE A suppressor device for a sprinkler head having a control chamber and a primary chamber interconnected by a passage including a unidirectional valve member for permitting flow through the passage from the primary chamber to the control chamber when the pressure in the primary chamber exceeds that in the control chamber and preventing flow in the other direction through the passage from the control chamber to the primary cham ber when the pressure in the control chamber exceeds that in the primary chamber.

FIELD OF INVENTION This invention relates to a suppressor device for an automatic on-otf sprinkler head.

BACKGROUND OF THE INVENTION Conventional sprinkler heads now in general use employ a plug of fusible material which, when subjected to temperatures above a predetermined level, melts and opens the head permitting water or other fire quenching fluid to escape and douse the fire. Since by operation of the head the plug is destroyed, the head remains on and continues to spue forth fluid even after the temperature has subsided. Recent activity in the field of sprinkler heads has produced an improved automatic on-ofi sprinkler head which turns on when the temperature reaches a predetermined level and automatically turns off when the temperature decreases below that level. One type of automatic on-off sprinkler head has a control chamber and a primary chamber which are flooded with the fluid. When the pressure in the chambers is more or less equal a spring bias force is permitted to close the head. The pressure in the chambers is permitted to equalize through an interconnecting passage. In the event of a fire a heat responsive device included in the head operates to vent the control chamber causing the pressure therein to be quickly decreased. The resulting pressure differential produces a force differential which enables the force developed by the pressure in the primary chamber to overcome the spring bias force and open the head. Since the sprinkler head is connected directly on line the head is constantly subject to variations in line pressure. Over a period of time the line pressure fluctuates upward and downward. If a decrease in pressure is gradual the pressure in the control chamber follows closely that in the primary chamber and little excess force is developed. If the decrease in pressure is sudden the pressure in the control chamber lags that in the primary chamber because of the time required for the pressures in the two chambers to equalize through the interconnecting passage. But this lag is not a problem in such cases because such a lag leaves the pressure in the control chamber higher than that in the primary chamber, and that condition can only produce a force that reinforces the closing force on the head. However, when increases in line pressure are considered the result is somewhat different. If an increase in pressure is gradual the pressure in the control chamber follows closely that in the primary chamber and little excess force is developed. But if an increase is sudden the pressure rise in the control chamber lags that in the primary chamber because of the time required for the pressures to equalize through the interconnecting passage. The momentary 5 greater pressure in the primary chamber can develop an excess force that opposes the closing force on the head. Thus if the increase in pressure is sufficiently sudden and sufliciently large the head may be improperly turned on. The chances of such an accidental turning on are increased when a sudden increase has followed a gradual decrease which has lowered the pressure in the control chamber.

SUMMARY OF INVENTION It is therefore an object of this invention to provide a suppressor device for suppressing spurious operation of a sprinkler head due to variations in line pressure.

It is a further object of this invention to provide a suppressor device for reducing backflow from the control chamber to the primary chamber of a sprinkler head.

It is a further object of this invention to provide a suppressor device which permits each increase in line pressure to be communicated to the control chamber but prevents communication to the control chamber of each decrease in pressure.

This invention features a suppressor device for a sprinkler head having a primary chamber and a control chamber interconnected by a passage. A unidirectional valve member permits flow through the passage from the primary chamber to the control chamber when the pressure in the primary chamber exceeds that in the control chamber but prevents flow in the other direction through the passage from the control chamber to the primary chamber when the pressure of the control chamber exceeds that in the primary chamber.

DISCLOURE OF PREFERRED EMBODIMENTS Other objects, features and advantages will occur from the following description of preferred embodiments and the accompanying drawings, in which:

FIG. 1 is a cross-sectional elevational view of an automatic on-ofi sprinkler head with a suppressor device according to this invention.

FIG. 2 is a cross-sectional elevational view of an alternative automatic on-oif sprinkler head with a suppressor device according to this invention.

The sprinkler head of this invention may be constructed using a housing and a movable partition which sealingly engages with the housing to provide a primary chamber and a control chamber. The housing includes an inlet port and an outlet port in the primary chamber; the inlet port is adapted for connection with a source of fire quenching fluid which is distributed through the outlet port. A passage interconnecting the two chambers, preferably located in the partition, permits the fluid provided at the inlet port to fill the control chamber as well as the primary chamber. Thus the pressure in the two chambers equalizes and the resultant force on the partition is balanced. A valve element connected to the partition is provided to close the outlet port. A biasing device, such as a spring, is used to apply a positive force to the partition in this balanced condition to insure proper seating of the valve element with the outlet port. The outlet port may include a valve seat and the valve element may be made of resilient material to improve the valving action. A control valve in the control chamber is opened by a heat responsive device when a predetermined temperature is reached. Upon the opening of this control valve the fluid in the control chamber is vented to a lower pressure, usually atmospheric pressure, so that the pressure in the control chamber is substantially reduced relative to that in the primary chamber. The difference in pressure between the two chambers produces a resultant force on the partition sufiicient to move it and so also move the valve element away from the outlet port. The sprinkler head is now on and discharges the fire quenching fluid. After the fire subsides and the temperature decreases the heat responsive device permits the control valve, usually spring loaded, to return to the closed position. The fluid entering through the inlet port enters through the passage interconnecting the chambers and fills the control chamber and enables the pressures in the two chambers to once again equalize. When the pressures are equalized the spring force moves the partition to position the valve element to close the outlet port and shut ofl? the sprinkler head.

In one embodiment, FIG. 1, sprinkler head includes a housing 12 with a partition 14 that creates two chambers, primary chamber 16 and control chamber 18, a control valve 20, spring 21, heat responsive device 22, and suppressor device 23.

Housing 12 includes nipple 24, upper section 26 and lower section 28 joined together at seam 30 where there may be located an O ring 32 for additional sealing. Inlet port 34 is formed by nipple 24 fitted in collar 36 and outlet port 38 is formed at collar 40. Nipple 24 extends through control chamber 18 into primary chamber 16. Raised shoulder 42 provides a valve seat 44 for valve element 46 connected to partition 14 by bracket 48 which is formed with large holes 50 to permit free flow of fluid therethrough. Valve element 46 is preferably formed of resilient material such as rubber and fastened in place by stem 52. A rigid cap 54 may be used to prevent distortion of valve element 46. At the lower end of stem 52 there is, secured by screw 56, distributor plate 58 for distributing the fire quenching fluid.

Partition 14 includes cylindrical base 60, cylindrical neck 62 and intermediate annular member 64. Base slidingly engages section 28 of housing 12 and has a channel 66 for retaining O ring 68. Neck 62 slidingly engages nipple 24- and includes a channel 70 for retaining O ring 72. Passage 74 interconnects chambers 16 and 18 to permit chamber 18 to fill from chamber 16 and to permit the pressures in the chambers to equalize. A screen 75 may be used to prevent dust particles from reaching passage 74.

Suppressor device 23 may include a unidirectional check valve, cuff 80, provided at passage '74 to help prevent sudden changes in line pressure in chamber 16 from accidentally turning on head 10. Cuff is a fiap of resilient material, such as rubber, whose lower periphery 81 tightly grips the base of cylindrical neck 62 and whose upper periphery 83 is free to flap against neck 62 to seal the end of passage 74 in chamber 18. Cuff 80 permits flow through passage 74 from chamber 16 to chamber 18 when line pressure increases but prevents backflow from chamber 18 to chamber 16 when line pressure decreases. Suppressor device 23 provides two functions. -It prevents back-flow from chamber 18 to chamber 16 when the line pressure in chamber 16 decreases. This back-fiow, if permitted, would lower the pressure in chamber 18 and make the head more vulnerable to spurious operation by a subsequent sudden surge or increase in line pressure. Suppressor device 23 also enables an increase in line pressure in chamber 16 to be communicated through passage 74 to chamber 18 by 'pushing cuif 80 away from the end of passage 74. A subsequent return to normal line pressure or decrease in line pressure in chamber 16 does not reduce the pressure in chamber 18 because cuif 80 prevents back-flow. Thus cuff 80 functions to accumulate in chamber 18 increases in line pressure in chamber 16; chamber 18 thereby stores higher pressures and enhances the ability of the hdad to suppress unwanted operation caused by sudden pges or increases in line pressure.

Control valve 20 includes a valve element on valve stem 92 which passes through vent hole 94 and supports hood 96. Valve element 90 including resilient portion 91 is urged closed against seat 98 by spring 100 in screened enclosure 102.

Heat responsive device 22 includes a bimetallic element 104 mounted on bracket 106 fastened to section 26 of housing 12. Screw 108 threadably engages with holes in bimetallic element 104 and the top and bottom of bracket 106 to provide adjustment of bimetallic element 104. The neck 110 of hood 96 is engaged in hole 112 in bimetallic element 104.

In operation, at normal temperatures, control valve 20 is held closed by spring 100; the pressure in chamber 18 is equal to that in chamber 16 so that the force exerted by spring 21 on partition 14 holds valve element 46 against seat 44 closing outlet port 38 and maintaining head 10 in the off condition. When the surrounding temperature increases to a predetermined level bimetallic element 104 reacts by moving downward at its free end thereby moving valve element 90 off its seat 98 and opening control valve 20. The fluid in chamber 18 is thus vented to the atmosphere through vent hole 94 thereby reducing the pressure in chamber 18. The difference in pressure thus created between chambers 16 and 18 produces a force on partition 14 suflicient to overcome that executed by spring 21 and partition 14 is moved upward. Valve element 46 fixed to partition 14 is likewise moved upward off of seat 44 and outlet port 38 is opened. Head 10 is now in the on condition and fire quenching fluid is discharged from outlet port 38 and distributed by distributor plate 58.

After the fire is out and the temperature decreases, the free end of bimetallic element 104 moves upwardly and permits hood 96 stem 92 and valve element 90' to move upward under the urging of spring 100' until valve element 90 is once again closed on seat 98. When control valve 20 is closed, fluid entering through passage 74 begins to accumulate in chamber 18 and the pressure in chamber 18 approaches that in chamber 16. When the pressures in the two chambers are substantially equal the force of spring 21 moves partition 14 downwardly and valve element 46 closes outlet port 38 restoring head 10' to the off condition.

In an alternative embodiment, FIG. 2, sprinkler head 210 includes a housing 212 with a partition 214 that creates two chambers, primary chamber 216 and control chamber 218, a control valve 220, the spring 221, heat responsive device 222, and suppressor device 223.

Housing 212 may include a nipple 224, upper section 226 and lower section 228 joined together at seam 230. Housing 212 includes an inlet port 234 and an outlet port 236 in primary chamber 216. Outlet port 236 may include outlet tube 238 fitted in collar 240. Tube 238 may be formed with a flared end 242 to provide valve seat 244 for valve element 246 connected to partition 214 by bracket 248. Valve element 246 is preferably formed of resilient material such as rubber and fastened in place by stem 252. A rigid cap 254 may be used to prevent distortion of valve element 246. At the lower end of stem 252 there is, secured by screw 256, distributor plate 258 for distributing the fire quenching fluid.

Partition 214 includes diaphragm 260 and slide 262 connected therewith. Diaphragm 260 may be a resilient material such as rubber and may include a peripheral bead 264 which when gripped between sections 226 and 228 at seam 230 serves to support diaphragm 260 and slide 262, and improve the seal between sections 226 and 228. Slide 262 may be interconnected with diaphragm 260 by means of support member 266 having a collar 268 fixed to slide 262 and an annular area 270' engaged with diaphragm 260 and a second support member 272 fixed to slide 262 and also engaged with diaphragm 260. Dia- Dhragm 260 is held between members 266 and 272 by any suitable means such as a friction fit, adhesive material or the like.

Slide 262 is a hollow tubular form which is adapted to slide on and sealingly engage guide 280 fixed to section 226.

Passage 290 interconnects chambers 216 and 218 to permit chamber 218 to fill from chamber 216 and to permit the pressures in the chambers to equalize. Member 272 has a plurality of holes 273 in it to provide free flow of fluid therethrough and to insure communication between passage 290 and the rest of chamber 216. A screen 292 may be used to prevent dirt particles from reaching pasage 290.

Suppressor device 223 may include a unidirectional check valve, fiat ring 300 provided at passage 290* to help prevent sudden changes in line pressure from accidentally turning on head 210 in the same manner as cufl? 80, FIG. 1. Ring 300 may be a flap of resilient material, such as rubber, whose inner periphery 302 tightly grips slide 262 and whose outer periphery 303 is free to flap against member 266 to seal the end of passage 290 in chamber 218. Ring 300 permits flow through passage 290 from chamber 216 to chamber 218 when line pressure increases but prevents back-flow from chamber 218 to chamber 216 when line pressure decreases. Suppressor device 223 provides two functions. It prevents back-flow from chamber 218 to chamber 216 when the line pressure in chamber 216 decreases which back-fiow would lower the pressure in chamber 218 and make the head more vulnerable to spurious operation by a subsequent sudden surge or increase in line pressure following the decrease in pressure. Suppressor device 223 also enables an increase in line pressure in chamber 216 to be communicated through passage 290 to chamber 218 by pushing ring 300 away from the end of passage 290. A subsequent return to normal line pressure or decrease in line pressure in chamber 216 does not reduce the pressure in chamber 218 because ring 300 prevents back-flow. Thus ring 300 functions to accumulate in chamber 218 increases in line pressure in chamber 216; chamber 218 thereby stores higher pressures and enhances its ability to suppress unwanted operation by sudden surges or increases in line pressure.

Control valve 220 includes a valve element 310 on valve Stern 312 which passes through vent hole 314 and supports hood 316. Valve element 310 including resilient portion 311 is urged closed against seat 318 by spring 320 in screened enclosure 322.

Heat responsive device 222 includes a bimetallic element 324 mounted on bracket 326 fastened to section 226 of housing 212. Screw 328 is threadably engaged in holes in bimetallic element 324 and the top and bottom of bracket 326 to provide adjustment of bimetallic element 324. The neck 330 of hood 316 is engaged in hole 332 in bimetallic element 334.

In operation, at normal temperatures, control valve 220 is held closed by spring 320, the pressure in chamber 218 is equal to that in chamber 216 so that the force exerted by spring 221 on partition 214 holds valve element 246 against seat 244 closing outlet port 236 and maintaining head 210 in the ofi condition. When the surrounding temperature increases to a predetermined level bimetallic element 324 reacts by moving downward at its free end thereby moving valve element 310 off its seat 318 and opening control valve 220. The fluid in chamber 218 is thus vented to the atmosphere through vent hole 314 thereby reducing the pressure in chamber 218. The difference in pressure thus created between chambers 216 and 218 produces a force on partition 214' sufiicient to overcome that exerted by spring 221 and partition 214 is moved upward. Valve element 246 fixed to partition 214 is likewise moved upward off of seat 244 and outlet port 236 is opened. Head 210 is now in the on condition and fire quenching fluid is discharged from outlet port 236 and distributed by distributor plate 258.

After the fire is out and the temperature decreases, the

free end of bimetallic element 324 moves upwardly and permits hood 31-6, stem 312 and valve element 310 to move upward under the urging of spring 320 until valve element 310 is once again closed on seat 318. When control valve 220 is closed, fluid entering through passage 29 0 begins to accumulate in chamber 218 and the pressure in chamber 218 approaches that in chamber 216. When the pressures in the two chambers are substantially equal the force of spring 221 moves partition 214 downwardly and valve element 246 closes outlet port 238 restoring head 210 to the olf condition.

Other embodiments will occur to those who are skilled in the art and are within the following claims.

What is claimed is:

1. An automatic on-ofi sprinkler head comprising:

a housing;

a movable partition sealingly engaging said housing for dividing said housing into two chambers, a primary chamber and a control chamber; said housing including an inlet port in said primary chamber adapted for connection with a source of fire quenching fluid, and an outlet port in said primary chamber for dispensing fire quenching fluid;

a control valve in said control chamber;

a heat responsive device for operating said control valve to turn on the sprinkler head above a predetermined temperature and turn off the sprinkler head below that temperature;

a valve element connected with said partition for closing said outlet port;

biasing means for producing a force on said partition to urge said valve element to close said outlet port;

a passage interconnecting said primary and control chambers for enabling equalization of pressure therein; and

a unidirectional valve member for permitting flow through said passage from said primary chamber to said control chamber when the pressure in said primary chamber exceeds that in said control chamber and preventing flow in the other direction through said passage from said control chamber to said primary chamber when the pressure in said control chamber exceeds that in said primary chamber.

2. The sprinkler head of claim 1 in which said unidirectional valve member includes a flap of resilient material mounted in said control chamber covering said passage.

3. The sprinkler head of claim 1 in which said movable partition includes a base for sealingly, slidingly engaging said housing and a neck for sealingly, slidingly engaging said inlet port and an intermediate member interconnecting said base and said neck.

4. The sprinkler head of claim 3 in which said base and said neck are generally cylindrical and said intermediate member is generally annular.

5. The sprinkler head of claim 3 in which said inlet port includes an inlet tube, extending through said control chamber into said primary chamber, for sealingly slidingly engaging said neck.

6. The sprinkler head of claim 1 in which said passage extends through said partition.

7. The sprinkler head of claim 1 in which said outlet port includes a valve seat for sealing engagement with said valve element.

8. The sprinkler head of claim 1 in which said valve element includes a resilient material.

9. The sprinnkler head of claim 1 in which said biasing means includes a spring member located in said control chamber.

10. The sprinkler head of claim 1 further including a distributor device for distributing the fluid discharged from said outlet port.

11. The sprinkler head of claim 1 in which said partition includes a diaphragm sealingly engaged with said housing.

12. The sprinkler head of claim 11 in which said partition further includes a slide member connected with said diaphragm.

13. The sprinkler head of claim 12 in which said slide member includes an intermediate member for interconnecting said slide member and said diaphragm.

14. The sprinkler head of claim 12 further including a guide member mounted within said housing for slidingly engaging said slide member.

15. An automatic on-otf sprinkler head including a housing, a movable partition sealingly engaging said housing for dividing said housing into two chambers; a primary chamber and a control chamber, said housing including an inlet port in said primary chamber adapted for connection with a source of fire quenching fluid, and an outlet port in said primary chamber for dispensing fire quenching fluid, said movable partition including a base for sealingly slidingly engaging said housing, a neck for sealingly slidingly engaging said inlet port, and an intermediate member interconnecting said base and said neck, a control valve in said control chamber, a heat responsive device for operating said control valve to turn on said sprinkler head above a predetermined temperature, and turn off said sprinnkler head below that temperature, a valve element connected with said partition for closing said outlet port; biasing means for producing a force on said partition to urge said valve element to close said outlet port, a passage interconnecting said primary and control chambers for enabling equalization of pressure therein, and a unidirectional valve member for permitting flow through said passage from said primary chamber to said control chamber when the pressure in said primary chamber exceeds that in said control chamber and preventing flow in the other direction through said passage from said control chamber to said primary chamber when the pressure in said control chamber exceeds that in said primary chamber.

16. The sprinkler head of claim 15 in which said unidirectional valve member includes a flap of resilient material mounted in said control chamber covering said passage.

17. An automatic on-otf sprinkler head, including a housing, a movable partition sealingly engaging said housing for dividing said housing into two chambers: a primary chamber and a control chamber, said partition including a diaphragm sealingly engaged with said housing and a slide member connected with said diaphragm, said housing including an inlet port in said primary chamber adapted for connection with a source of fire quenching fluid and an outlet port in said primary chamber for dispensing fire quenching fluid and a guide member for slidingly, sealingly engaging said slide member, a control valve in said control chamber, a heat responsive device for operating said control valve to turn on said sprinkler head above a predetermined temperature, and turn olf said sprinkler head below that temperature, a valve element connected with said partition for closing said outlet port biasing means for producing a force on said partition to urge said valve element to close said outlet port, a passage interconnecting said primary and control chambers for equalization of pressure therein, and a unidirectional valve member for permitting flow through said passage from said primary chamber to said control chamber when the pressure in said primary chamber exceeds that in said control chamber and preventing flow in the other direction through said passage from said control chamber to said primary chamber when the pressure in said control chamber exceeds that in said primary chamber.

18. The sprinkler head of claim 17 in which said unidirectional valve member includes a flap of resilient material mounted in said control chamber covering said passage.

19. A suppressor device for a sprinkler head having a control chamber and a primary chamber interconnected by a passage comprising:

a unidirectional valve member for permitting flow through said passage from said primary chamber to said control chamber when the pressure in said primary chamber exceeds that in said control chamber and preventing flow in the other direction through said passage from said control chamber to said primary chamber when the pressure in said control chamber exceeds that in said primary chamber.

20. The suppressor device of claim 19 in which said unidirectional valve member includes a flap of resilient material mounted in said control chamber covering said passage.

21. In an automatic on-off sprinkler head including a housing, a movable partition sealingly engaging said housing for dividing said housing into two chambers; a primary chamber and a control chamber, said housing including an inlet port in said primary chamber adapted for connection with a source of fire quenching fluid, and an outlet port in said primary chamber for dispensing fire quenching fluid, said movable partition including a base for sealingly slidingly engaging said housing, a neck for sealingly slidingly engaging said inlet port, and an intermediate member interconnecting said base and said neck, a control valve in said control chamber, a heat responsive device for operating said control valve to turn on said sprinkler head above a predetermined temperature, and turn off said sprinkler head below that temperature, a valve element connected with said partition for closing said outlet port; biasing means for producing a force on said partition to urge said valve element to close said outlet port, and a passage interconnecting said primary and control chambers for enabling equalization of pressure therein, the improvement comprising a unidirectional valve member for permitting flow through said passage from said primary chamber to said control chamber when the pressure in said primary chamber exceeds that in said control chamber and preventing flow in the other direction through said passage from said control chamber to said primary chamber when the pressure in said control chamber exceeds that in said primary chamber.

22. The sprinkler head of claim 21 in which said unidirectional valve member includes a flap of resilient material mounted in said control chamber covering said passage.

23. In an automatic on-otf sprinkler head including a housing, a movable partition sealingly engaging said housing for dividing said housing into two chambers; a primary chamber and a control chamber, said partition including a diaphragm sealingly engaged with said housing and a slide member connected with said diaphragm, said housing including an inlet port in said primary chamber adapted for connection with a source of fire quenching fluid and an outlet port in said primary chamber for dispensing fire quenching fluid and a guide member for slidingly, sealingly engaging said slide member, a control valve in said control chamber, a heat responsive device for operating said control valve to turn on said sprinkler head above a predetermined temperature, and turn off said sprinkler head below that temperature, a valve element connected with said partition for closing said outlet port, biasing means for producing a force on said partition to urge said valve element to close said outlet port, and a passage interconnecting said primary and control chambers for equalization of pressure therein, the improvement comprising a unidirectional valve member for permitting flow through said passage from said primary chamber to said control chamber when the pressure in said primary chamber exceeds that in said control chamber and preventing flow in the other direction through said passage from said control chamber to said primary chamber when the pressure in said control chamber exceeds that in said primary chamber.

.24. The sprinkler head of claim 23 in which said unidirectional valve member includes a flap of resilient ma- 9 10 terial mounted in said control chamber covering said 3,254,870 6-/ 1966 1Haessler et al 25143 passage. 3,279,743 10/1966 La Garza 251-43 References Cited 3,451,422 6/1969 Chorkey 137-525 3,459,217 8/1969 Callahan 137525 UX UNITED STATES PATENTS 3,556,122 1/1971 Laerdal 137-5251): 917,292 4/1909 Hankee et a1. 169-37 5 1;; guliok RICHARD A. SCHACHER, Primary Examiner urns 2,235,304 3/1941 Toussaint 251 45 GRANT Asslstam Exammer 2,891,760 6/1959 Dewar 2s1-44 3,160,212 12/1964 Reid 16920 169 37 

